Various hand cleaner foam dispensers are known with pump arrangements for simultaneously passing a liquid and air through a foam inducing member to produce a foamed product and discharge the foamed product onto a user's hand. Such foam dispensers for dispensing liquid from a single reservoir are well known and as for example are taught in U.S. Pat. No. 7,303,099 to Ophardt issued Dec. 4, 2007 and U.S. Pat. No. 8,272,539 to Ophardt et al. issued Sep. 25, 2012.
Hand cleaner foam dispensers are known in which a pump arrangement in which liquid from a single reservoir is mixed with air and discharged as foam onto a user's hand. The present inventor has appreciated that previously known devices do not provide hand cleaner foam dispensers in which two liquid streams, for example, from two different reservoirs may be mixed and delivered to a person's hand as a foam.
Proprietary hand cleaner compositions are known which are adapted when dispensed through a foam generating pump arrangement to produce a foamed product. Such cleaning compositions include alcohol and water compositions and liquid soap compositions. The present inventor has appreciated that with many known cleaning compositions, difficulties arise in creating foam with optimized characteristics for hand cleaning. Difficulty in producing advantageous foam for hand cleaning particularly arises in respect of cleaning compositions including alcohol. Cleaning compositions containing alcohol have enhanced cleaning as the amount of alcohol is increased, for example, to above 40% by volume alcohol or more preferably above 60% by volume alcohol to provide for enhanced cleaning, however, difficulties in producing advantageous foam for hand cleaning compositions containing alcohol increases as the concentration of alcohol is increased, particularly when the concentration of alcohol is increased above 40% by volume or above 60% volume.
Proprietary hand cleaning compositions may require particular additives such as foaming agents, surfactants and foam stabilizers. The present inventor has appreciated that difficulties arise in developing cleaning composition with suitable components to provide an advantageous foam for cleaning since legal protection on proprietary cleaning compositions can restrict the use of particular compositions.
The present inventor has also appreciated that known pump arrangements to produce foam that draw liquid from a single reservoir and/or having a single pump arrangement limit the extent to which advantageous foam may be developed and/or different cleaning compositions and additives may be utilized.